. generalize libexec slightly to get some more necessary information
from ELF files, e.g. the interpreter
. execute dynamically linked executables when exec()ed by VFS
. switch to netbsd variant of elf32.h exclusively, solves some
conflicting headers
Pipes consist of two filps (read filp and write filp) and a shared
vnode. When the writer leaves the filp reference count drops to
zero and subsequent find_filp()s should not find the filp when a
reader looks for it and the reader gets EOF. However, the pipe()
system call tries to find two filps, marks them in use, and only
after a successful node creation on PFS, overwrites the shared
vnode with the new vnode. Consequently, this leaves a small window
where a just closed 'pipe write filp' gets reused and marked as
present, before becoming the actual new 'pipe write filp' for a new
pipe. A reader for the old pipe will think a writer is present and
wait for that writer to write something or to leave; both actions
should revive the suspended reader. This will never happen and the
reader will be stuck forever.
When running out of worker threads to handle device replies a dead
lock resolver thread is used. However, it was only used for FS
endpoints; it is now used for "system processes" (drivers and FS
endpoints). Also, drivers were marked as system process when they
were not "forced" to map (i.e., mapping was done before endpoint was
alive).
By making m_in job local (i.e., each job has its own copy of m_in instead
of refering to the global m_in) we don't have to store and restore m_in
on every thread yield. This reduces overhead. Moreover, remove the
assumption that m_in is preserved. Do_XXX functions have to copy the
system call parameters as soon as possible and only pass those copies to
other functions.
Furthermore, this patch cleans up some code and uses better types in a lot
of places.
use the user-supplied point to lookup which region to perform brk() on,
and if it's a reasonable one, do it, no matter what vm's notion of the
heap region is.
This Shared Folders File System library (libsffs) now contains all the
file system logic originally in HGFS. The actual HGFS server code is
now a stub that passes on all the work to libsffs. The libhgfs library
is changed accordingly.
Previously, the mmap address (if given) was merely used as a lower
bound, and then possibly overriden with a hint. Now, the mapping is
first tried at the exact given address. If that fails, the start of
the mmap range is used as lower bound (which is then still overridden
by the hint for efficiency).
This allows two pages to be mapped in at predefined addresses, where
the second address is lower than the first. That was not possible.
remove some old minix-userland-specific stuff
. /etc/ttytab as a file, and minix-compat function (fftyslot()),
replaced by /etc/ttys and new libc functions
. also remove minix-specific nlist(), cuserid(), fttyslot(), v8 regex
functions and <compat/regex.h>
. and remaining minix-only utilities that use them
. also unused <compat/pwd.h> and <compat/syslog.h> and
redundant <sys/sigcontext.h>
- add files needed for acpi, ahci, fbd, vfs to libminc
- remove "-lc" from their respective makefiles
- remove setenv from libminc (requires initialization)
On MFS file systems, the stat(2) call now counts indirect blocks as
part of the st_blocks calculation, in addition to proper initial
rounding of the file size. The returned value is now a true upper
bound on the actual number of 512-byte blocks allocated to the file.
As before, it is not accurate for sparse files.
- libnetsock - internal implementation of a socket on the lwip
server side. it encapsulates the asynchronous protocol
- lwip server - uses libnetsock to work with the asynchronous
protocol
- if an operation (R, W, IOCTL) is non blocking, a flag is set
and sent to the device.
- nothing changes for sync devices
- asyn devices should reply asap if an operation is non-blocking.
We must trust the devices, but we had to trust them anyway to
reply to CANCEL correctly
- we safe sending CANCEL commands to asyn devices. This greatly
simplifies the protocol. Asynchronous devices can always reply
when a reply is ready and do not need to deal with other
situations
- currently, none of our drivers use the flags since they drive
virtual devices which do not block
- select_request_async() returns no ops by default
- wantops in do_select() always set correctly, do_select() does
not need a special case for SUSPEND (and ugly code)
When VFS detects that an FS has crashed and tries to clean up
resources, it marks fairly late in the process that a vmnt is not
to be used again (to send requests to). This allows a thread to
become blocked on a vmnt after all blocked threads were stopped, but
before it finds out it shouldn't try to send to that vmnt.
If the provided path was only a single component (i.e., without
slashes), then last_dir would return early and skip the symlink
detection (i.e., check whether the path ends in a symlink and resolve
that first before returning). This bug triggered an assert in open
which expects that an advance after an last_dir (with VMNT_WRITE lock)
does not yield another vmnt lock.
The assert was meant as an additional check to the assert in link.c:198.
The reasoning behind the assert in link.c:198 is that once you've
obtained a write lock on a vmnt, you can't get an additional read lock
on the same vmnt. However, that does not always hold for the assert in
path.c:281 where the situation could be that you've obtained a read lock
and managed to get another read lock (this is possible). In other words,
the assert in path.c:281 is not the right place to check for that
situation.
- Fix locking bug when unable to send DEV_SELECT request. Upon failure
VFS tried to cancel the select operation, but this failed due to trying
to lock a filp that was already locked to send the request in the first
place. Do_select_request now handles locking of filps itself instead of
relying on the caller to do it. This fixes a crash when killing INET.
- Fix failure to revive a process after a non-blocking select operation
yielded no ready select operations when replying DEV_SEL_REPL1.
- Improve readability by using OK, SUSPEND, and standard error values as
results instead of having separate macros in select.
- Don't print not having a driver for a major device; after killing a driver
select will trigger this printf.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.
Changes in this commit:
. drop boot monitor -> allowing dropping ack support
. facility to copy ELF boot files to /boot so that old boot monitor
can still boot fairly easily, see UPDATING
. no more ack-format libraries -> single-case libraries
. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
. drop several ack toolchain commands, but not all support
commands (e.g. aal is gone but acksize is not yet).
. a few libc files moved to netbsd libc dir
. new /bin/date as minix date used code in libc/
. test compile fix
. harmonize includes
. /usr/lib is no longer special: without ack, /usr/lib plays no
kind of special bootstrapping role any more and bootstrapping
is done exclusively through packages, so releases depend even
less on the state of the machine making them now.
. rename nbsd_lib* to lib*
. reduce mtree
- When cancelling ioctls, VFS did not remember which file descriptor
to cancel and sent bogus to the driver.
- Select state was not cleaned up when select()ing process was
interrupted.
- Process trying to do a system call at the exact same time as a user
trying to interrupt the process, could cause the system call worker
thread to overwrite state belonging to the worker thread trying to
exit the process. This led to hanging threads and eventual system hang
when this happens often enough.
When a mount operation fails and the FS exits, free_proc could try and
clean up resources associated with the mount point before the mount
thread itself can do that. However, the clean up procedure should only
clean up resources that were actually in use.
Currently, all servers and drivers run as root as they are forks of
RS. srv_fork now tells PM with which credentials to run the resulting
fork. Subsequently, PM lets VFS now as well.
This patch also fixes the following bugs:
- RS doesn't initialize the setugid variable during exec, causing the
servers and drivers to run setuid rendering the srv_fork extension
useless.
- PM erroneously tells VFS to run processes setuid. This doesn't
actually lead to setuid processes as VFS sets {r,e}uid and {r,e}gid
properly before checking PM's approval.
When an FS crashes, VFS will clean up resources tied to that FS:
- Pending requests to the FS are canceled (i.e., fail with EIO)
- Threads waiting for a reply are stopped (i.e., fail with EIO)
- Open files are marked invalid. Future operations on a file descriptor
will cause EBADF errors.
- vmnt entry is cleared, so in-flight system calls that got past the
file descriptor check but not yet talking to the crashed FS, will
fail with EIO.
- The reference counter of the mount point is decreased, effectively
removing the crashed FS from the file system tree. Descendants of
this part of the tree are unreachable by means of a path, but can
still be unmounted by feeding the block special file to unmount(2).
This patch also gets rid of the "not a known driver endpoint" messages
during shutdown.
User processes can send signals with number up to _NSIG. There are a few
signal numbers above that used by the kernel, but should explicitly not
be included in the range or range checks in PM will fail.
The system processes use a different version of sigaddset, sigdelset,
sigemptyset, sigfillset, and sigismember which does not include a range
check on signal numbers (as opposed to the normal functions used by normal
processes).
This patch unbreaks test37 when the boot image is compiled with GCC/Clang.
Last_dir didn't consider paths that end in a symlink and hence didn't
actually return the last_dir when provided with one. For example,
/var/log is a symlink to /usr/log. Issuing `>/var/log' would trigger
an assert in AVFS, because /var/ is not the actual last directory; /usr/
is.
Last_dir now verifies the final component is not a symlink. If it is, it
follows the symlink and restarts finding of the last the directory.
When a lock has read-serialized and read-only locks, releasing the read-
serialized lock would not set the state to read-only when no other locks
were pending.
. also implement now-possible fsck -p option
. allows unconditional fsck -p invocation at startup,
only checking each filesystem if not marked clean
. mounting unclean is allowed but is forced readonly
. updating the superblock while mounted is now not
allowed by mfs - must be done (e.g. by fsck.mfs)
on an unmounted fs
. clean flag is unset by mfs on mounting, and set by
mfs on clean unmounting (if clean flag was set at
mount time)
Signed-off-by: Ben Gras <ben@minix3.org>
. use dirty marking hooks to check and warn
when inodes/bufs are marked dirty on a readonly
mounted fs
. add readonly mount checks to restore readonly
mounting
Signed-off-by: Ben Gras <ben@minix3.org>
. No functional change
. Only serves to get hooks to do checks in
. e.g. should things be marked dirty when we are
mounted readonly
Signed-off-by: Ben Gras <ben@minix3.org>
Some code relies on having the file descriptor in m_in.fd. Consequently,
m_in is not only used to provide syscall parameters from user space to
VFS, but also as a global variable to store temporary data within VFS.
This has the ugly side effect that m_in gets overwritten during core
dumping.*
To work around this problem VFS now uses a so called "scratchpad" to
store temporary data that has to be globally accessible. This is a simple
table indexed by process number, just like fproc. The scratchpad allows
us to store the buffer pointer and buffer size for suspended system calls
(i.e., read, write, open, lock) instead of using fproc. This makes fproc
a bit smaller and fproc iterators a bit faster. Moreover, suspension of
processes becomes simpler altogether and suspended operations on pipes
are now less of a special case.
* This patch fixes a bug where due to unexpected m_in overwriting a
coredump would fail, and consequently resources are leaked. The coredump
was triggered with:
$ a() { a; }
$ a
This patch makes PFS, EXT2 and MFS print only once that they're out of
space. After freeing up space and running out of space again, the message
will be printed again also.
The nbyte in read(int fildes, void *buf, size_t nbyte) is unsigned,
so although technically we're doing the same comparison, this is more
in line with POSIX.
The comparison was moved to read_write as that routine is used within
VFS to let it VFS write out coredumps.
When a process wants something done from VFS, but VFS has no worker
threads available, the request is stored and executed later. However,
when PM also sends a request for that process at the same time, discard
the pending request from the process and give priority to PM. The request
PM sends is either an EXIT or a DUMPCORE request, so we're not interested
in executing the pending request anyway.
This patch provides basic protection against damage resulting from
differently compiled servers blindly copying tables to one another.
In every getsysinfo() call, the caller is provided with the expected
size of the requested data structure. The callee fails the call if
the expected size does not match the data structure's actual size.
Using sendrec directly only results in problems. While it is not
clear whether using fs_sendrec is the best option, it is at least
an improvement.
Also remove some legacy cruft.
This patch separates the character and block driver communication
protocols. The old character protocol remains the same, but a new
block protocol is introduced. The libdriver library is replaced by
two new libraries: libchardriver and libblockdriver. Their exposed
API, and drivers that use them, have been updated accordingly.
Together, libbdev and libblockdriver now completely abstract away
the message format used by the block protocol. As the memory driver
is both a character and a block device driver, it now implements its
own message loop.
The most important semantic change made to the block protocol is that
it is no longer possible to return both partial results and an error
for a single transfer. This simplifies the interaction between the
caller and the driver, as the I/O vector no longer needs to be copied
back. Also, drivers are now no longer supposed to decide based on the
layout of the I/O vector when a transfer should be cut short. Put
simply, transfers are now supposed to either succeed completely, or
result in an error.
After this patch, the state of the various pieces is as follows:
- block protocol: stable
- libbdev API: stable for synchronous communication
- libblockdriver API: needs slight revision (the drvlib/partition API
in particular; the threading API will also change shortly)
- character protocol: needs cleanup
- libchardriver API: needs cleanup accordingly
- driver restarts: largely unsupported until endpoint changes are
reintroduced
As a side effect, this patch eliminates several bugs, hacks, and gcc
-Wall and -W warnings all over the place. It probably introduces a
few new ones, too.
Update warning: this patch changes the protocol between MFS and disk
drivers, so in order to use old/new images, the MFS from the ramdisk
must be used to mount all file systems.
. make procfs check it
. detects pm/procfs mismatches
. was triggered by ack/clang pm/procfs:
add padding to mproc struct to align ack/clang layout
to fix this
The "bdev" library provides basic primitives for file systems to talk
to block device drivers, hiding the details of the underlying protocol
and interaction model.
This version of libbdev is rather basic. It is planned to support the
following features in the long run:
- asynchronous requests and replies;
- recovery support for underlying block drivers;
- retrying of failed I/O requests.
The commit also changes our block-based file systems (mfs, ext2, isofs)
to make use of libbdev.
In certain cases, a process ID may be reused between two lazy updates
of procfs's PID table. If the new associated process slot has a lower
index than the old one, this will trigger an assert in vtreefs, as the
new PID name entry is added before the old one is removed. This patch
fixes the problem by always first removing old PID name entries before
adding new ones.
Bug reported by Stephen Hatton.
PUFFS file systems need to make back calls for every operation we
send to them. Consequently, they cannot handle block reads and writes
themselves. Instead, the root file system has to do it (for now).
When the mount operation causes an FS to make a back call, AVFS now
concludes that every block read and write for that FS has to go
through the root file system.
In some places it was assumed that PATH_MAX does not include a
terminating null character.
Increases PATH_MAX to 1024 to get in sync with NetBSD. Required some
rewriting in AVFS to keep memory usage low (the stack in use by a thread
is very small).
. move cache size heuristic from mfs there
so mfs and ext2 can share it
. add vfs credentials retrieving function, with
backwards compatability from previous struct
format, to be used by both ext2 and mfs
. fix for ext2 - STATICINIT was fed no.
of bytes instead of no. of elements, overallocating
memory by a megabyte or two for the superblock
During shutdown all processes are semi-exited and FSes are unmounted.
This semi-exit causes trouble for FUSE mounts as they still need access
to file descriptors and working directory in order to unmount.
. move mfs-specific struct, constants to mfs/, so
mfs-specific, on-disk format structs and consts are
fully isolated from generic structs and functions
. removes de and readfs utils
. only use for single-page invalidations initially
. shows tiny but statistically significant performance
improvement; will be more helpful in certain VM debug
modes
. ipc wants to know about processes that get
signals, so that it can break blocking ipc operations
. doing it for every single signal is wasteful
and causes the annoying 'no slot for signals' message
. this fix tells vm on a per-process basis it (ipc)
wants to be notified, i.e. only when it does any ipc calls
. move ipc config to separate config file while we're at it
. it's a good extra interface to have but doesn't
meet standardised functionality
. applications (in pkgsrc) find it and expect
full functionality the minix mmap doesn't offter
. on the whole probably better to hide these functions
(mmap and friends) until they are grown up; the base system
can use the new minix_* names
. MAP_SHARED was used to implement sysv shared memory
. used to signal shareable memory region to VM
. assumptions about this situation break when processes
use MAP_SHARED for its normal, standardised meaning
POSIX truncate specification says "Upon successful completion, if
the *file size is changed*, this function shall mark for update the
st_ctime and st_mtime fields of the file." This patch prevents
changing of the date fields when the size stays the same.
* VFS and installed MFSes must be in sync before and after this change *
Use struct stat from NetBSD. It requires adding new STAT, FSTAT and LSTAT
syscalls. Libc modification is both backward and forward compatible.
Also new struct stat uses modern field sizes to avoid ABI
incompatibility, when we update uid_t, gid_t and company.
Exceptions are ino_t and off_t in old libc (though paddings added).
